利用微计算机断层扫描定量研究选择性激光熔化Ti6Al4V合金缺陷的几何特征及形成机理  

Quantitative study of geometric characteristics and formation mechanism of porosity defects in selective laser melted Ti6Al4V alloy by micro-computed tomography

作　　者：安娜莹 帅三三 陈超越 雷力明 王江 任忠鸣 Na-ying AN;San-san SHUAI;Chao-yue CHEN;Li-ming LEI;Jiang WANG;Zhong-ming REN(State Key Laboratory of Advanced Special Steels,School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;AECC Shanghai Commercial Aircraft Engine Manufacturing Co.,Ltd.,Shanghai 201306,China)

机构地区：[1]上海大学材料科学与工程学院省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444 [2]中国航发上海商用飞机发动机制造有限公司,上海201306

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第10期2986-3002,共17页中国有色金属学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2019YFA0705300);Shanghai Rising-Star Program,China(Nos.20QA1403800,21QC1401500);Shanghai Science and Technology Committee,China(Nos.21511103600,20511107700,19DZ1100704)。

摘　　要：增材制造(AM)部件内部形成的缺陷对打印零件的力学性能具有不利影响。缺陷对零件性能的影响因其几何特征的不同而不同。利用X射线计算机层析成像(XCT)研究不同打印参数下36个块状Ti6Al4V样品的孔隙缺陷特征。根据样品中孔隙的几何特征,将孔隙缺陷分为4种类型:球形、椭圆形、长条形和不规则形。在所有工艺参数下,长条形状缺陷所占比例最大,并且随着扫描速度的提高,不规则形状缺陷所占比例逐渐增大。另外,分析单道和多道试样中缺陷逐渐积累规律。随着层的叠加,孔隙逐渐积累,而适当的搭接率可能会熔化道之间的气孔。表面粗糙度和熔池润湿对缺陷的形成有很大的影响。The defects formed inside the additive manufactured(AM)part have a detrimental effect on the mechanical performance of the printed component.The effect of defects on the performance of parts varies with their geometry features.The characteristics of porosity defects in 36 bulk Ti6Al4V specimens with different printing parameters were investigated via X-ray computed tomography(XCT).The porosity defects are classified into four types:sphericalshaped,elliptical-shaped,elongated-shaped and irregularly-shaped pores,based on their geometric characteristics.Elongated-shaped defects account for the largest proportion of defects with all printing parameters,and the proportion of irregularly-shaped defects enhances with the increase of scanning speed.The characteristics of gradual accumulation of defects in single-track and multi-track samples were also analyzed.Porosity may gradually accumulate with the overlay of layers,while the appropriate overlapping rate may melt the pores between the tracks.The formation of defects is greatly influenced by surface roughness and pool wetting.

关 键 词：选择性激光熔化 X射线计算机断层扫描 气孔缺陷 3D几何形态 形成机制 TI6AL4V合金 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TG146.23[一般工业技术—材料科学与工程] TN249[金属学及工艺—金属材料]